Rick Akins Posted October 1, 2010 Share Posted October 1, 2010 AS I remmeber from last year I get hum on the radio only when the lightorama sequence plays... I can play mp3s through my computer and I don't get hum. This leads me to think it's coming from the sequenceing program,but don't know that to be true....any Ideas? Link to comment Share on other sites More sharing options...
LightORamaDan Posted October 1, 2010 Share Posted October 1, 2010 Rick Akins wrote: AS I remmeber from last year I get hum on the radio only when the lightorama sequence plays... I can play mp3s through my computer and I don't get hum. This leads me to think it's coming from the sequenceing program,but don't know that to be true....any Ideas?I will close the other thread that was started on this topic a short time ago so the answers will be focused here.You are going to need to do a few more tests and answer a few more questions.1. Light O Rama uses Windows Media Player (WMP) to generate the audio, when you tested outside the Sequence Editor were you using WMP to test? If not rerun the test using WMP when LOR is not running. It could be that sound generated by WMP is poor quality.2. It is unlikley (almost impossible) that the LOR applications cause a hum BUT there are some things that could be happening. For example the USB cable and/or Lights and Light controllers will be generating a lot of RF interference. This generally does not affect FM very much but it can. So I recommend that if the coluperate is not WMP that you try running the audio without the USB adapter plugged into the PC with the Sequence Editor or without the CAT5 plugged into the USB adapter for the Show Player and see what happens.Because this works okay in some cases and not in others, something electrical OR the media player being used is going to be the issue here.Dan Link to comment Share on other sites More sharing options...
Rick Akins Posted October 1, 2010 Author Share Posted October 1, 2010 Thanks for the reply....It's the kind of hum that you can't hear while the music is playing...You can only hear it before the music and after it's over....I am running the cat5 cable through the same outside wall as the antenna cable...would the data flow through the cat 5 cable cause this hum...If yes would wireless to the controler stop it.. Link to comment Share on other sites More sharing options...
FischLights Posted October 1, 2010 Share Posted October 1, 2010 What is your power supply for the FM transmitter? I used a Belkin FM transmitter and I also had a humm in between songs . I switched the power source on the transmitter from an AC/DC adaptor to the 5 volt USB port and it works great, no hum Link to comment Share on other sites More sharing options...
gizmomkr Posted October 1, 2010 Share Posted October 1, 2010 I suspect the "humm" is being caused by a ground loop / bad ground.These can be introduced many different ways. dirty dimming circuits also have a tendancy to produce EMI (google it)A couple of things to try:check all your grounds - computer ground, transmitter ground, LOR controller ground. Make sure they are all grounded well. use a circuit tester (home depot sells one that plugs into an outlet with 3 lights) this will give oyu a basic ground check.I also like dan's idea of disconnecting the controller for a test.I dont THINK dirty dimming is the source because I presume all levels are at zero with no music ( or inbetween songs) But I think you have a good chance that an opto-isolated adapter will fix the humm. http://store.lightorama.com/usisad.htmlI suspect there is a difference in ground potential between your transmitter and your controller - the opto-isolator would break the ground between the two, therefore removing the humm.Bad or dirty power cupply on your transmitter is also an option. for a test - run your transmitter off a battery pack, see if the humm goes away. If it does, I would get a better power source. or depenting on the voltage, you may be able to power your transmitter via the Pc's PSU.finally it could be a ground loop via the pc audio feed. you can find a ground loop isolator in many car audio shops (both wal-mart and radio shack had them last I checked. ) they will probably have RCA connectors on then, but its easy to convert RCA to 1/8.After the grounds check, I would go with the audio isolator because its about 15.00. if the problem doesnt go away, then I'd go for the opto isolator for the USB-rs485One more thing. Check all your levels. An old Audio rule of thumb was "anything above unity is thehnically distortion" Its not really 100% true with digital components these days, but the humm could simply be noise from your source.Your transmitter probably wants a line-level signal. your pc has lots of faders that cant put the signal above line level - try pulling your "wave out" and master volumes down to 50% or lower.Something here should help. keep us posted. Link to comment Share on other sites More sharing options...
Rick Akins Posted October 1, 2010 Author Share Posted October 1, 2010 Thanks for your reply..again....My house does have ground wires except on the circuits I have wired in. So there is no ground loop. Link to comment Share on other sites More sharing options...
gizmomkr Posted October 1, 2010 Share Posted October 1, 2010 Dont knock the idea of grounds just because your outlet has a shiny wire on it. Try a battery pack on the transmitter and a audio loop isolator - I would bet my lunch it has some impact. (but I didnt have lunch today so if im wrong, you get nothing)the "humm" is a sign of interference from something - ground is where signal drains to eliminate interference.You can have "a ground" but not a good ground - or a good ground to different places. Everything SHOULD go to the panel, and then to a rod pounded into the earth, but some folks use water pipe, (thinking it was copper or lead into the ground... but it turned out ot be pvc in between) or someone grounds to a metal box and 50 ft down the line someone ran out of wire, so they just stole it from the ground wire.... contractors do come crazy stuff.Im just saying for 15.00 it has a really good shot at fixing your problem.Just this week, I had an install with crazy fuzzy lines scroling across 4 different LCD monitors. even the tester said the ground was good..... Well it turned out it WAS there, but it was never tightened, ground clamps were loose at the outlets, and at the pannel.... It still tested good, but looked like crapp. couple turns of a screw driver, and wala. Link to comment Share on other sites More sharing options...
Rick Akins Posted October 1, 2010 Author Share Posted October 1, 2010 I will try that,but I know for a fact that there are no ground wires in my house...I will try a battery back up and the iso Link to comment Share on other sites More sharing options...
rikerz Posted October 2, 2010 Share Posted October 2, 2010 I have had the same hum in my transmitter since it was new, I personally think my problem is that is a cheap transmitter. I almost have all the hum out but changing the antenna. I used the antenna off a handheld scanner and now it works alot better. Link to comment Share on other sites More sharing options...
Randy Posted October 2, 2010 Share Posted October 2, 2010 This sounds a little like an automatic gain control issue. The hum is minimized when a music signal is playing, but when that signal stops, something may be trying to raise the gain (hence the hum level) on the audio path?What kind of transmitter are we talking about? Link to comment Share on other sites More sharing options...
FischLights Posted October 2, 2010 Share Posted October 2, 2010 This is the transmitter I am using, I know it's cheap, but it works good now. The power source is the USB port, 5 Volts. Attached files Link to comment Share on other sites More sharing options...
Rick Akins Posted October 2, 2010 Author Share Posted October 2, 2010 thanks for your reply. I will have to get back with you on the kind of transmitter..I'm at work right now and I'm not sure..will have at to take a look,but I know it puts out 1watt of power. Link to comment Share on other sites More sharing options...
gizmomkr Posted October 2, 2010 Share Posted October 2, 2010 NOT having ground wires will deffinately cause this....Also a "battery backup" liek a UPS isnt quite what I meant - If youre transmitter will take a battery (like AA / or 9volt) connecting to a UPS WILL MAKE THE PROBLEM WORSE - when that thing kicks over to battery, its noisy dirty power, and not a sine wave.... all lbad stuff for fm transmitter.I sent a bunch of other into to you in a pm, but I would really recomend a slightly better transmitter. I spent about 50.00 on mine, and I think TJ bid the same one down to about 40.00 - I posted a thread on it, its a much more powerfull unit.It may or may not have the same issue, but its a better unit, and cant hurt.But I would really focus on the ground - you shoudl have a ground on all your stuff. Link to comment Share on other sites More sharing options...
Rick Akins Posted October 2, 2010 Author Share Posted October 2, 2010 Heres what I'm going to do. I will wire in a grounded plug. An then use a USB485B along with a wireless link to the controlers. I think that will fix my problem..I think my transmitter is a ramesy stereo up to 1 watt of power. I will plug my computer into the plug and also the transmitter. Link to comment Share on other sites More sharing options...
Brian Mitchell Posted October 2, 2010 Share Posted October 2, 2010 1 watt? Really? That is WAY over your legal limit for a private use station. Link to comment Share on other sites More sharing options...
gizmomkr Posted October 3, 2010 Share Posted October 3, 2010 I confused Ricks post with whoever posted the belkin.Ramsey is a great unit - Keep it. The ELL will definately break any ground loop back to the PC, so by all means, yes, try that.What are you powering the Ramsey with ? Link to comment Share on other sites More sharing options...
Greg Young Posted October 4, 2010 Share Posted October 4, 2010 Brian Mitchell wrote: 1 watt? Really? That is WAY over your legal limit for a private use station.Ramsey stopped making the 1 watt "export only" after FCC actions a few years back.A Ramsey (25B, 100B, etc), without an external amplifier, will have a maximum of 25 mw output, which is more than adequate. With an external antenna it will exceed the part 15 range easily...Greg Link to comment Share on other sites More sharing options...
Rick Akins Posted October 5, 2010 Author Share Posted October 5, 2010 well it would be 1 watt if the pot was turned up all the way. It is not. Link to comment Share on other sites More sharing options...
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